The process of decision making around the most appropriate AAC and aided communication method is something that our team is constantly involved in and thinking about.
One tool that we occasionally use to help people think about their communication and where AAC or aided communication might fit in is a communication diary. We have often found (in practice and research) that it is very difficult for people to think about their communication (‘communication introflection’ i’ve called it) and this is a tool to help people do this.
You can CommunicationDiary, though it comes with no endorsement or guarantees! We would welcome comments from people on what they use and comments on this diary.